Nowadays, handheld electronic devices, such as: smart phones, mobile phones, flat computers and notebooks, are all necessities of life, so how to quickly and easily charge the rechargeable batteries of the foregoing handheld electronic devices becomes a key factor improving people's living standard.
Most people charge handheld electronic devices with a charger at home or in the office. However, travelers probably are unable to charge their mobile phones and other electronic devices on the road. Of course, some people might carry portable power sources (batteries) in case of need, but portable power sources also need to be charged with a charger. Therefore, so far, no effective means is available to solve the problem of charging on the road.
Some people have developed suitcases, which can generate power, but these suitcases have never been put into the market because their design has the following problems:
1. The internal mechanism of the suitcase has large friction force (internal resistance), making the suitcase difficult to move.
2. The generated current is too low to effectively charge handheld electronic devices.
3. The suitcase is often moved around or kept in a humid and dusty place. It does not have effective damp-proof and dust-proof design, thus resulting in failure of the charging device.
4. The rechargeable battery is not protected. Battery damage is extremely dangerous, even may trigger explosion. Besides, battery design must also conform to the provisions of international airline companies.